Automated sidewall fusing apparatus

ABSTRACT

The present invention is directed to a method and apparatus for fusing a sidewall pipe onto a host pipe using pneumatic equipment. The functions of the fusing apparatus are controlled by a programmable computer. Further, as each fuse is performed, a GPS system provides and stores the geographical location of the fuse.

FIELD OF THE INVENTION

The present invention is directed to the field of fusing a polyolefinpipe onto a sidewall of another polyolefin pipe of equal or lesserdiameter.

BACKGROUND OF THE INVENTION

The use of polyolefin pipe has become commonplace for utilities. Otherindustrial uses of polyolefin pipe have increased with the developmentof fusible polyolefin materials. Fusible materials such as polyethyleneand polyethylene alloys are being substituted for steel, ductile iron,clay, concrete, and bell and spigot PVC pipe for industrial uses inwhich high pressure and heat are not a concern. These polyolefinmaterials are typically lighter in weight and almost completelyunaffected by corrosion. For example, polyolefin pipe is being used totransport corrosive chemicals, waste water, potable water, storm water,and for irrigation systems, leachate systems and petrochemicalcollection systems.

A number of circumstances will require fusing two pieces of polyolefinpipe together. The process of fusing polyolefin pipe consists of placingtwo matching surfaces on either side of a heat source, heating thesurfaces to a predetermined temperature, removing the heat source, andforcing the two surfaces together under pressure.

Many factors affect the fusing of two pieces of polyolefin pipe.Polyolefin pipe is manufactured in many different wall thicknesses anddiameters. In addition, fuses of the two pipes may be performed in awide range of environments, from shops with controlled conditions toopen pits subject to ground and weather conditions. An effective fusingapparatus would have to adapt to all such conditions. Further, dependingon the result desired, the two pieces of pipe may be fused end to end(butt fusing) or with the end of one joined to the sidewall of the hostpipe (sidewall fusing). Butt fusing is generally easier to accomplish.Sidewall fusing is accomplished by either of two methods: (1) fusing afabricated saddle with a pipe nipple already attached onto the sidewallof the host pipe; or (2) fusing onto the host pipe a pipe with a concaveradius on one end matching the convex radius of the host pipe.

Prior art devices accomplishing sidewall fusing are described in U.S.Pat. Nos. 3,998,682, 4,533,424, 4,542,892, and 5,613,807. Fusingmachines currently being used employ manually-operated screws,hand-pumped hydraulics, auxiliary-powered, high pressure hydraulics, ora combination of these in order to provide the movements and pressuresnecessary to complete a sidewall fusion. Machines employingmanually-operated screws or hand-pumped hydraulics are slow, preventingan operator from joining the heated surfaces together quickly after theheat source is removed. Auxiliary-powered, high-pressure hydraulicmachines must have valves, hoses, and cylinders capable of operating athigh pressures, making the machines heavy and expensive; additionally,replacement power units for such machines are not readily available atrental outlets and contractor supply houses.

U.S. Pat. No. 5,013,376 discloses and claims a method of heat fusingwhich uses hydraulics and is controlled by a programmable computer. Thepatent states generally that the apparatus can be used for sidewallfusing; however, the apparatus described would be unable to performsidewall fusions. For instance, the apparatus has no way of moving andattaching sidewall pipe (all movements described are along alongitudinal axis). No provision is made for fusing two different sizesof pipe, which would call for different soak times. Sidewall fusingrequires a special heating plate with concave and convex faces. Also,the apparatus described uses a facing tool (useless in sidewall fusing)but has no provision for making radius cuts.

SUMMARY OF THE INVENTION

The present invention is directed to the use of automated, pneumaticfusing equipment to fuse a piece of polyolefin pipe to the sidewall ofanother polyolefin pipe. The functions of the fusing equipment arecontrolled by a programmable computer. The operator of the machineselects options from a menu on a control panel, which is programmed toaccount for different pipe sizes and environmental conditions. Inaddition to controlling the pneumatically-operated functions, thecomputer records the date, time, size, and status (pass or fail) of thefuse. All this information may be stored and uploaded. Further, eachtime a fuse is performed, the computer automatically activates anonboard Global Positioning System (GPS) in order to provide thegeographical location of the fuse. Uploading the GPS location to acomputerized map results in a permanent geographical record of the fuse.

The invention consists of a base, extension rods, travel head, andcontrol panel. The base accommodates the pneumatically-activated pipeclamps and pneumatic valves for attaching the base to the host pipe; italso provides an attachment for the heating plate and the pneumaticcylinders that actuate the heating plate, as well as an attachment forthe two guide rods on which the travel head slides. The travel headmoves along the extendible guide rods; the distance traveled is thelength of the pipe being fused onto the sidewall of the host pipe. Thetravel head provides the points of attachment for the pneumaticcylinders that raise and lower the stack (sidewall pipe), for theextension rod pneumatic clamps that secure the travel head as itautomatically adjusts for the length of the stack, for the bladder thatinflates to provide attachment to the stack, and for the pneumatictravel head controls. The control panel, which is attached to the fusingmachine by means of electric control cables, monitors the fusing machineand controls the pneumatic functions. In addition, the control panelhouses and operates the GPS system.

The use of pneumatics (air) to carry out the fusing process has noprecedent in the prior art. Prior art has depended on high-pressurehydraulics to perform fusing operations. However, in the presentinvention, pneumatics are used to raise and lower the heating elementand the sidewall pipe, to inflate the bladder, and to check the fuse.The advantages of pneumatics over hydraulics are numerous: aircomponents are lighter, cheaper, more widely available, and moreresponsive. The pneumatically-actuated system of this invention iseffective due to the use of additional heating time and to theapplication of pressure to the heating plate during the main heatingcycle, which forces the surface of the host pipe to conform to a truematching heating plate surface. Because pneumatics are used rather thanhydraulics, the sidewall pipe can be heated and fused to the host pipebefore much heat is dissipated, resulting in a strong fuse.

The primary object of this invention is to overcome the limitations ofthe prior art by providing a fusing apparatus which is completelyautomated, pneumatically-powered, lightweight, and operator-friendly.

A further object of this invention is to provide a portable fusingapparatus which can be moved, set up, and removed without mechanicalassistance. The apparatus can be hand carried on the job site, loweredby hand into a pit, removed by hand from a pit, and moved by hand fromfuse to fuse.

Another object of the invention is to provide a computer-controlledpneumatic fusing apparatus which has production line capabilitiesutilizing one computer and one power source to control one or morefusing machines.,

A still further object of this invention is to apply sequential pressureduring fusing, resulting in better pipe conformation, which yieldssuccessful fusing using less pressure.

Another object of the invention is to provide a method which allows twopipe surfaces to be fused, with minimal time elapsing between heatingand fusing.

Yet another object of the invention is to provide an apparatus which canadjust soak time during preheating of the pipes to be fused.

Still another object of the invention is to provide a system forrecording the geographic location of each fuse as it is made.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of the fusing machine of the presentinvention.

FIG. 2 is a side perspective view of the travel head portion of thefusing machine, showing parts of the travel head interior in cutaway.

FIG. 3 is a side perspective view of the base of the fusing machine,showing parts of the interior of the base in cutaway.

FIG. 4 is a top view of the control panel of the present invention.

FIGS. 5 through 13 are simplified side views of the sequence of stepsinvolved in the fusing process of the present invention. The fusingmachine is shown clamped onto the host pipe, with the stack (sidewallpipe) installed in the fusing machine.

FIG. 14 is a flow chart showing the necessary manual and automaticoperations involved in the fusing process of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the preferred fusing machine of the presentinvention is shown. The fusing machine 1, constructed primarily ofstainless steel and aluminum, includes a base 2, a hinged heating plate3 of Teflon-coated aluminum, a stack housing 4, radius plates 5a and 5bdisposed one on each side of the base 1, movable pipe clamping arms6a,6b, 6c, (6d hidden), a bladder 7, a bladder plate 8, extension rods9a, 9b, and a travel head 10. Heating plate pneumatic cylinders 11, oneon each side of the heating plate 3, control the movement of the heatingplate 3. Pipe clamping pneumatic cylinders 12a, 12b facilitate clampingthe fusing machine 1 to the host pipe.

Attached to the base 2 is a base control box 13 for housing pneumaticand electrical connections and solenoids. Information from the controlpanel 30 (shown in FIG. 4) is transmitted through the base electricalcontrol connection 14. Information from the control panel 30 is receivedat travel head electrical control connection 15, controlling verticalmovement of the travel head 10 along the extension rods 9a, 9b. Rodclamping cylinders 16a, 16b lock the travel head 10 in place.

FIG. 2 shows fusing pneumatic cylinder 17 disposed within the travelhead 10. Stack loading cylinder 18 is disposed within stack housing 4.Cylinder rods 19a, 19b between cylinders 17 and 18 are coupled togetherat 19c. At the lower end of stack loading cylinder 18 is a bladder plate8, and below that the bladder 7, an inflatable rubber plug. A notch 20prevents stack loading cylinder 18 from allowing the stack to rotate.Air is supplied to the fusing pneumatic cylinder 17 through travel headair connection 21. Electrically-activated air regulators 22 andsolenoids 23 control all functions of travel head 10. The travel head 10is connected to base 2 at extension rod ends 24a, 24b.

FIG. 3. shows only the base 2 of the fusing machine 1. The heating plate3 is in a raised position. In operation, it is lowered against aself-leveling, floating heating plate frame 25. The stack centeringplate 26 keeps the stack in proper alignment to the host pipe. Air issupplied to heating plate pneumatic cylinders 11 and pipe clampingpneumatic cylinders 12a, 12b through base air connection 27. Extensionrod connection ends 24a, 24b are threaded onto base connectors 28a, 28b.

FIG. 4 shows the control panel 30 which controls the automatic operationof the fusing machine 1. The control panel 30 is constructed ofhigh-impact plastic, with water resistant housing. The controls aremembrane switches. The control panel 30 has a menu display screen 31.Down arrow key 32 allows the operator to scroll down, while up arrow key33 allows the operator to scroll up through menu choices. X-key 34allows the operator to reject a choice, while .check mark.-key 35 allowsan operator to accept a choice. Heating plate switch 36a turns theheating plate 3 off, while heating plate switch 36b turns it on. Heatingplate cylinder control 37a causes the heating plate 3 to be lowered,while heating plate cylinder control 37b causes it to return to a raisedposition. The bladder control 38a causes the bladder 7 to deflate, whilethe bladder control 38b causes it to inflate. The travel head rodclamping cylinder control 39a releases the travel head 10, while thetravel head rod clamping cylinder control 39b extends and locks thetravel head 10. Stack control 40a lowers the stack, while stack control40b raises the stack. Pipe clamping arms control 41a releases the base 2from the host pipe, while pipe clamping arms control 41b clamps the baseto the host pipe. Auto setup control 42 actuates the automatic set upfunctions. Auto fuse control 43 actuates the fusing operation. Theinterrupt indicator 44 will light up if either a power failure or aheating plate 3 failure disrupts the fusing process. Fuse pass/failindicator 45 indicates whether the resulting fuse has been accomplished.

The control panel 30 is connected to its power supply at power supplyreceptacle 46. Computer interface 47 receives the cable which allows thecontrol panel 30 to transmit and receive information. Electrical cablesare connected to the control panel 30 at travel head cable connector 48and base cable connector 49.

Before operating the fusing machine 1 can be operated, a 110 voltelectrical supply is connected to the control panel 30 at power supplyreceptacle 46. Electrical cables connect the control panel 30 to thefusing machine 1; one runs between travel head cable connection 48 andthe travel head electrical control connection 15, the other between thebase cable connector 49 and the base electrical control connection 14.

Prior to fusing, the surface of the polyolefin host pipe must be free ofall contaminants. New pipe may be cleaned by rubbing the area to befused with 60 grit emery cloth or with alcohol. Pulled pipe (pipe pulledthrough the ground or along street surfaces) may have scratches, gougesand nicks, which can be cleaned by high pressure laser-jet washing or byusing a brush and alcohol.

The polyolefin sidewall pipe (called a stack) to be fused onto the hostpipe must also be prepared. One end of the stack is cut to conform tothe curvature of the outer surface (convex radius) of the host pipe. Thestack radius cut is roughened with a medium rasp, then cleaned asdescribed for the host pipe.

The automated fusing method of this invention utilizes software whichsets time sequences controlling the operation of the compressed airsolenoids, the actuating sequences of the solenoids, the parameters ofthe air test, the pass or fail specifications for the fuse, thetemperature parameters, and the GPS location data.

FIGS. 5 through 13 show the sequence of steps involved in the fusingprocess, in a very simplified fashion.

FIG. 5 shows the fusing machine 1 clamped to a host pipe 50. The stack(sidewall pipe) 51 is raised, as is the heating plate 3.

FIG. 6 shows the heating plate 3 in a lowered position, where it isheating a section of the host pipe 50. This is the beginning of thepre-heat cycle.

FIG. 7 shows the stack 51 lowered onto the heating plate 3 in order toseat the heating plate 3.

FIG. 8 shows the stack 51 raised away from the heating plate 3 toprevent the stack 51 from being prematurely heated.

FIG. 9 shows the stack 51 lowered onto the heating plate 3 in order toseat the heating plate 3 under pressure.

FIG. 10 shows the stack 51 raised away from the heating plate 3.

FIG. 11 shows the stack 51 lowered onto the heating plate 3 for apre-programmed timed heat. The stack 51 is under pressure to assure theheating plate 3 is concentric with the host pipe 50 and stack 51.

FIG. 12 shows the stack 51 after it has been raised and the heatingplate 3 being returned to a raised position.

FIG. 13 shows the stack 51 lowered onto the heated section of the hostpipe 50, to which it is fused. The pipes are left undisturbed in thisposition to allow the fuse to cool before the pressure test isperformed.

FIG. 14 shows the sequence of operations for completing a fuse,combining the necessary manual and automatic operations in a flow chart.As shown in FIG. 14, an operator will install software 55, whichcontrols the operation of the control panel 30 during each fusingoperation.¹

As shown in block 56, an attendant connects 1/8 air lines with 100 psito the travel head air connection 21 and to the base air connection 27.He uses two electrical lines to connect the control panel 30 to thefusing machine 1, and a 110 volt power source is connected to thecontrol panel 30.

When the power is turned on, the fusing machine 1 is in the defaultposition 57, with the heating plate 3 turned off and in the raisedposition, the pipe clamping pneumatic cylinders 12a, 12b off, all thecylinders extended, the bladder 7 deflated, and the fusing machine 1 inthe raised position.

The stack (sidewall pipe) 51 is manually installed 58 in the fusingmachine 1 between the bladder 7 and the top plate of the base 2, andinside the stack centering plate 26. The concave radius of the stack 51is situated in axial alignment with the convex radius on the host pipe50. The travel head 10 is lowered until the bladder 7 slides in thestack 51, then the bladder 7 is inflated 59. Upon activation, the travelhead rod clamping cylinders 16a, 16b hold the travel head 10 in place.

As shown in block 61, the operator lowers the fusing machine 1 onto thehost pipe 50 and activates the pipe clamping arms 6a, 6b,6c (6d) tosecure the fusing machine 1 onto the host pipe 50. (When fusing shortstacks in a shop situation, the fusing machine can be attached to thehost pipe before installation of the stacks.)

The operator checks the default menu display screen 31 on the controlpanel 30 to determine the current settings for pipe sizes, etc. Theoperator can scroll through the menu select 62 to choose the propersizes for the host pipe 50 and stack 51, and to choose a custom set-up,which takes into account different weather and environmental conditions.The menu also allows the operator to monitor the test pressure and checkthe DC voltage of the control panel 30, as well as the temperature ofthe heating plate 3. In addition, it displays the date and time, as wellas the GPS system latitude and longitude.

Upon accepting the menu parameters 63, the operator, as shown in block64, chooses the control panel display function "Auto Seat on Main,"selects "yes", and actuates the automatic set-up (auto setup control42). The stack loading cylinder 18 automatically extends, forcing thestack 51 onto the host pipe 50. The bladder 7 deflates, allowing thestack 51 radius to seat on the host pipe 50 radius. The rod clampingcylinders 16a, 16b retract. The bladder 7 inflates, holding the stack 51in place. The travel head 10 moves upward the combined length of thestack 51 and stack loading cylinder 18. The rod clamping cylinders 16a,16b extend, locking the travel head 10 in place. The stack loadingcylinder 18 retracts, causing the stack 51 to move upward, giving theheating plate 3 clearance to be lowered onto the host pipe 50. Theheating plate pneumatic cylinders 11 extend, and the heating plate 3lowers onto the host pipe 50. Stack loading cylinder 18 extends,lowering the stack 51 to the extended length of stack loading cylinder18. The travel head rod clamping cylinders 16a, 16b release, droppingthe travel head 10 and stack 51 approximately one inch until the stackmakes contact with the heating plate 3. The travel head rod clampingcylinders 16a, 16b extend, locking the travel head 10 in place. Stackloading cylinder 18 retracts, raising the stack 51. The heating plate 3is raised away from the host pipe 51.

Next, the heating plate 3 is actuated 65. Typically, the heating plate 3requires twenty minutes to reach fusing temperature. (When the fusingmachine 1 is being used in a shop situation, the heating plate 3 can beactivated as soon as the power is turned on; however, when the fusingmachine 1 is being used in a pit or augured hole, requiring moving andlowering the fusing machine 1, the heating plate 3 should be activatedafter the fusing machine 3 is attached to the host pipe 50.)

When the operator selects the Auto Fuse Control 43, he activates theautomatic fusing functions 66. The timing and sequence of the airsolenoids is controlled by the computer instructions in the controlpanel 30. The air pressure settings are controlled by air regulators 22located on the fusing machine 1, which are activated by the controlpanel 30.

In systems equipped with the GPS (Global Positioning System), selectionof the auto fuse control 43 automatically activates the GPS system,locating the latitude and longitude of the fuse and storing theinformation in volatile memory; this information can be uploaded laterto create a permanent location, time and date of the fuse, its status(pass or fail), as well as host pipe and stack size.

The control panel 30 monitors the temperature of the heating plate 3.When it reaches approximately 495° F., the automatic fusing sequencewill commence². At the beginning of the preheat cycle, the heating plate3 is lowered onto the host pipe 50. At a timed interval, the stack 51 islowered, under pressure, onto the heating plate 3 by the stack loadingcylinder 18 for approximately five seconds. The stack 51 is then raisedby stack loading cylinder 18. These steps may be repeated, depending onthe diameter and SDR (standard dimension ratio) of the host pipe 50.This process facilitates the seating of the heating plate 3 on the hostpipe 50 and ensures the ovality of the portion of the host pipe 50 whichcomes in contact with the heating plate 3. The preheat cycle lasts fromtwo to four minutes.

During the main-heat cycle, the stack loading cylinder 18 extends,forcing the stack 51, onto the concave top side of the heating plate 3.Pressure is applied for a pre-programed period of time to force theradius of the host pipe and the radius of the stack 51 to fully conformto the convex and concave radius of the heating plate 3. The pressureexerted by the stack loading cylinder 18 is isolated and exhausted. Thestack 51 remains in contact with the heating plate 3, which is incontact with the host pipe 50 for a pre-programmed time to complete themain heat. The stack loading cylinder 18 retracts, raising the stack 51,as the heating plate pneumatic cylinders 11 retract, raising the heatingplate 3 away from the host pipe 50. The heating plate 3 automaticallyturns off. (This action takes place over a one-second period.)

The fusing pneumatic cylinder 17 and stack loading cylinder 18 extend,forcing the stack 51 under pressure onto the heated portion of the hostpipe 50 under pressure for a pre-programmed period of time, resulting inthe migration of the stack 51 into the host pipe 50. The pressure isreduced to zero. The fused stack 51 and host pipe 50 are now fused. Thefuse is allowed to cool for a pre-programmed time, approximately sixminutes.

To perform the fuse test, the control panel 30 actuates air solenoids23, which causes an adjustable, regulated air pressure to be directedinto the stack 51 through an access path in the bladder 7. The controlpanel 30 isolates the pressure source and monitors the pressure insidethe stack 51 for a pre-programmed period of time at a pre-programmedpressure. Depending on the test parameters programmed into the on-boardcomputer memory of the control panel 30 as compared to the monitored airpressure in the stack 51, the control panel 30 will display a pass orfail result on the menu display screen 31. In addition, a green ".checkmark." or red "x" will flash on the fuse pass/fail indicator 45.

The GPS data and fuse information are stored in the volatile memory,where the information can be uploaded subsequently to create a permanentrecord of the fuse.

The control panel 30 automatically releases the air test pressure in thestack 51. The bladder 7 is deflated, and the movable pipe clamping arms6a, 6b, 6c, (6d) are released. The fusing machine 1 is then ready to beremoved.

We claim:
 1. A process for fusing a polyolefin stack pipe to thesidewall of a polyolefin main pipe using a computer and a fusingapparatus with a travel head and a base inside which a heating platewith a concave upper surface and a convex lower surface is disposed, theprocess comprising the steps of:(1) providing power to said computer;(2) connecting said computer to said fusing apparatus; (3) providingsaid computer with software capable of processing parameters for fusingpolyolefin pipe with input data related to characteristics of said stackpipe and said main pipe; (4) connecting pneumatic air lines to saidfusing apparatus; (5) installing said stack pipe in said fusingapparatus; (6) positioning said stack pipe perpendicular to a section ofsaid main pipe; (7) clamping said base onto said main pipe; (8)performing steps of a set-up sequence, including determining(a) distancefrom an upper surface of said heating plate in its lowered position toan uppermost portion of said heating plate in a fully raised position;(b) thickness of said heating plate; (c) length of said stack pipe; (d)distance the stack pipe will migrate into the main pipe; and (e) settingsaid travel head in a position which accounts for the measurements in(a) through (d) in order to maintain proper pressure and clearancesduring each cycle of the process; (9) heating said heating plate; (10)lowering the heating plate onto said main pipe; (11) pneumaticallyapplying pressure onto said upper surface of said heating plate in orderto seat said heating plate; (12) raising said stack pipe; (13)pneumatically applying pressure onto said upper surface of said heatingplate for a time period sufficient to cause a heated portion of saidmain pipe to conform to said convex lower surface of said heating plate;(14) exhausting pressure from said fusing apparatus; (15) continuing toheat said heating plate; (16) raising said heating plate from betweensaid lower end of said stack pipe and said heated portion of said mainpipe; (17) pneumatically lowering said lower end of said stack pipe ontosaid heated portion of said main pipe, under pressure, resulting in afusion of said pipes; (18) allowing said fusion to cool; (19) testingsaid fusion for its ability to withstand pressure; (20) locating thelatitude and longitude of said fusion by utilizing anautomatically-activated Global Positioning System (GPS) and storing saidlatitude and longitude in said computer's memory for later uploading. 2.A process according to claim 1 wherein step (8) is performedautomatically.
 3. A process according to claim 1 wherein the lower endof the stack pipe is pneumatically lowered onto the upper concavesurface of said heating plate, thereby pneumatically applying pressurein steps (11) and (13), and, in step (13), causing a lower end of saidstack pipe to conform to said concave upper surface.
 4. A processaccording to claim 1 wherein step (19) is performed automatically beforethe fusing apparatus is removed from the host pipe.
 5. A processaccording to claim 1 wherein steps (10), (12), and (16) occurpneumatically.
 6. A process according to claim (1) wherein steps (11)and (12) may be repeated.
 7. An improved fusing apparatus of the type inwhich a base clamps onto a polyolefin main pipe, rods extend from saidbase to a movable travel head with holding means for a polyolefin stackpipe, and a heating plate is hinged to said base, wherein theimprovement comprises:(1) pneumatic means for clamping said base ontosaid main pipe, raising and lowering said travel head, raising andlowering said heating plate, providing pressure to seat said heatingplate onto the main pipe, and providing pressure to fuse said stack pipeto a portion of said main pipe; (2) a computer for controlling andmonitoring the sequence of pneumatically-actuated movements of saidfusing apparatus according to programmed parameters; (3) anautomatically-activated Global Positioning System (GPS) which locatesthe latitude and longitude of said fusion, storing said latitude andlongitude in said computer's memory for later uploading.